<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Frontend
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Output.php 23775 2011-03-01 17:25:24Z ralph $
 */

/**
 * @see Zend_Cache_Core
 */
require_once 'Zend/Cache/Core.php';

/**
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Frontend
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Cache_Frontend_Output extends Zend_Cache_Core {
	
	private $_idStack = array ();
	
	/**
	 * Constructor
	 *
	 * @param  array $options Associative array of options
	 * @return void
	 */
	public function __construct(array $options = array()) {
		parent::__construct ( $options );
		$this->_idStack = array ();
	}
	
	/**
	 * Start the cache
	 *
	 * @param  string  $id                     Cache id
	 * @param  boolean $doNotTestCacheValidity If set to true, the cache validity won't be tested
	 * @param  boolean $echoData               If set to true, datas are sent to the browser if the cache is hit (simpy returned else)
	 * @return mixed True if the cache is hit (false else) with $echoData=true (default) ; string else (datas)
	 */
	public function start($id, $doNotTestCacheValidity = false, $echoData = true) {
		$data = $this->load ( $id, $doNotTestCacheValidity );
		if ($data !== false) {
			if ($echoData) {
				echo ($data);
				return true;
			} else {
				return $data;
			}
		}
		ob_start ();
		ob_implicit_flush ( false );
		$this->_idStack [] = $id;
		return false;
	}
	
	/**
	 * Stop the cache
	 *
	 * @param  array   $tags             Tags array
	 * @param  int     $specificLifetime If != false, set a specific lifetime for this cache record (null => infinite lifetime)
	 * @param  string  $forcedDatas      If not null, force written datas with this
	 * @param  boolean $echoData         If set to true, datas are sent to the browser
	 * @param  int     $priority         integer between 0 (very low priority) and 10 (maximum priority) used by some particular backends
	 * @return void
	 */
	public function end($tags = array(), $specificLifetime = false, $forcedDatas = null, $echoData = true, $priority = 8) {
		if ($forcedDatas === null) {
			$data = ob_get_clean ();
		} else {
			$data = & $forcedDatas;
		}
		$id = array_pop ( $this->_idStack );
		if ($id === null) {
			Zend_Cache::throwException ( 'use of end() without a start()' );
		}
		$this->save ( $data, $id, $tags, $specificLifetime, $priority );
		if ($echoData) {
			echo ($data);
		}
	}

}
